The present disclosure relates to snowmobiles and, more particularly, to snowmobiles for use in deep snow applications.
Generally, snowmobiles are available for various applications such as deep snow, high performance, luxury touring, and trail riding, for example. Regardless of the application, certain structural components are common to many snowmobiles. For example, snowmobiles typically include a frame, a track assembly, a power train, skis, and at least one suspension system, as are illustrated in U.S. Patent Application Publication No. 2011/0139528, filed on Feb. 14, 2011, U.S. Patent Application Publication No. 2011/0192667, filed on Feb. 4, 2011, U.S. Pat. No. 7,353,898, issued on Apr. 8, 2008, and U.S. Provisional Application Ser. No. 61/513,949, filed on Aug. 1, 2011, the complete disclosures of which are expressly incorporated by reference herein.
One common area for snowmobiles generally relates to the overall architecture, where a frame includes a tunnel and a front chassis portion which retains the power train, and a front suspension that mounts skis to the frame. A drive shaft is typically mounted to the front chassis portion and includes drive sprockets for powering the belt. A chain case is also typically provided to transfer power from an engine or CVT to the drive shaft. Reference is made to U.S. Pat. No. 7,694,768 which shows a typical snowmobile drivetrain with a drive shaft and an upper jack shaft that drives the drive sprockets through the chain case, the subject matter of which is incorporated herein by reference.
In the case of mountain or deep snow snowmobiles, one common characteristic is to provide an elongated endless belt to provide a longer footprint for the belt, and a lower pressure for the snowmobile for flotation in deep snow. An elongated tunnel is also provided to cover the extended belt. A front body typically surrounds at least the front frame portion to enclose the engine and other mechanical components. Reference is made to U.S. Pat. No. 7,870,920 and to U.S. patent application Ser. No. 13/021,586 both of which show deep snow snowmobiles, the subject matter of each being incorporated herein by reference. A present version of a snowmobile frame for deep snow is shown in FIG. 1.